Ship Wake Detection in SAR Images with Complex Backgrounds Using Morphological Component Analysis

The detection of ship wakes in SAR images is helpful not only for estimating the speed and the direction of moving ships, but also for finding ship objects which are far smaller than ship wakes. Facing the problem that the existing detection methods based on the line detection can be only used for SAR images under the simple sea background conditions, a novel ship wake detection method for SAR images with the complex backgrounds using the morphological component analysis is proposed. Relied on the basic principle that each component can only be sparsely represented by a specific dictionary, suitable basis functions are selected for the dictionary construction according to the "line" singularity of ship wakes and the "point" singularity of sea-surface textures respectively, and the ship wake structure component and the sea-surface texture component are consequently separated in the sense of sparse representation. Then, the enhancement of ship wake structure component is realized through the reconstruction of the high-frequency coefficients of the shearlets transform. And finally, the ship wake lines are detected by using the Radon transform. Both the qualitative and the quantitative experimental results show that, the proposed method conspicuously outperforms the existing methods for the ship wake detection in SAR images, especially under the complex sea background conditions.